Macroscopic and mesoscopic biomechanical analysis of the bone unit in idiopathic scoliosis / 生物医学工程学杂志

To investigate the effects of postoperative fusion implantation on the mesoscopic biomechanical properties of vertebrae and bone tissue osteogenesis in idiopathic scoliosis, a macroscopic finite element model of the postoperative fusion device was developed, and a mesoscopic model of the bone unit was developed using the Saint Venant sub-model approach. To simulate human physiological conditions, the differences in biomechanical properties between macroscopic cortical bone and mesoscopic bone units under the same boundary conditions were studied, and the effects of fusion implantation on bone tissue growth at the mesoscopic scale were analyzed. The results showed that the stresses in the mesoscopic structure of the lumbar spine increased compared to the macroscopic structure, and the mesoscopic stress in this case is 2.606 to 5.958 times of the macroscopic stress; the stresses in the upper bone unit of the fusion device were greater than those in the lower part; the average stresses in the upper vertebral body end surfaces were ranked in the order of right, left, posterior and anterior; the stresses in the lower vertebral body were ranked in the order of left, posterior, right and anterior; and rotation was the condition with the greatest stress value in the bone unit. It is hypothesized that bone tissue osteogenesis is better on the upper face of the fusion than on the lower face, and that bone tissue growth rate on the upper face is in the order of right, left, posterior, and anterior; while on the lower face, it is in the order of left, posterior, right, and anterior; and that patients' constant rotational movements after surgery is conducive to bone growth. The results of the study may provide a theoretical basis for the design of surgical protocols and optimization of fusion devices for idiopathic scoliosis.

The Influence of Thread Tap Mismatch on Pedicle Screw Pullout Strength / A influência da incompatibilidade do macho de rosca na resistência à extração do parafuso pedicular

Abstract Objective We aimed to study the "in vitro" pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw, SpineGuard Inc, Boulder, Colorado, USA), a screw designed to be inserted using a direct insertion technique. Methods Dynamic Surgical Guidance Screws of 5.5 and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16g/cm3). According to the experimental group, screws were inserted without pilot hole, with pilot without tapping, undertapping and line-to-line tapping. Screw pullout tests were performed using a universal test machine after screw insertion into polyurethane blocks. Results Screws inserted directly into the polyurethane blocks without pilot hole and tapping showed a statistically higher pullout strength. Insertion of the screw without tapping or with undertapping increases the pullout screw strength compared with lineto-line tapping. Conclusion Dynamic Surgical Guidance Screw showed the highest pullout strength after its insertion without pilot hole and tapping.

Resumo Objetivo Nosso objetivo foi estudar a resistência à extração "in vitro" do parafuso SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct (Parafuso DSG Guia Cirúrgico Dinâmico, SpineGuard Inc, Boulder, Colorado, USA), um parafuso projetado para ser inserido utilizando a técnica de inserção direta. Métodos Os parafusos DSG de 5,5 e 6,5 mm foram introduzidos em blocos de poliuretano com densidade de 10 PCF (0,16g/cm3). De acordo com o grupo experimental, os parafusos foram inseridos sem um orifício piloto, com um orifício piloto sem o macheamento, com macheamento e com macheamento linha a linha. Os testes de extração do parafuso foram realizados em uma máquina de teste universal, após a inserção do parafuso em blocos de poliuretano. Resultados Os parafusos inseridos diretamente nos blocos de poliuretano sem o orifício piloto e o macheamento mostraram uma resistência à extração estatisticamente maior. A inserção do parafuso sem o macheamento ou com o macho de menor diâmetro aumenta a resistência à extração do parafuso em comparação com o macheamento linha a linha. Conclusão O parafuso DSG apresentou a maior resistência à extração após a inserção sem o orifício piloto e o macheamento.

Does range of motion measurement and reference values differ?: a multi-centered study

This study is aimed to estimate and measure reference values in the normal range of motion of extremity joints in females and to provide a database for the assessment of impairments related to the mobility of the joints. This observational cross-sectional study was conducted at seven major educational institutes areas of Rawalpindi and Islamabad in Pakistan from January to June 2020 with a sample size of 600 healthy females aged 15 to 45 years and divided into three groups through non-probability sampling technique. In study Instruments, an electronic Goniometer was used for the measurement of the range of motions for different joints and then those ranges were recorded. The questionnaire had two sections demographic characteristics and ROM for both upper and lower limbs. Data was analyzed using SPSS V21. A p < 0.05 was considered statistically significant.In the result,Out of 600 participants,there was a statistically significant difference of (p < 0.001) in both upper and lower extremities motion between all the three groups for the measurements and noticeably no significant difference (p > 0.005) between group 1, 2 comparisons for the knee joint extension.To conclude, In most joints, the range of motion increases with age. The transition from group 1 to group 2 was aided by increased hormone participation in growth, an active lifestyle, and generally good health. Because of degenerative changes and joint stiffness, group 3's range of motion deteriorated, leading to a sedentary lifestyle and lack of physical activity. Standardized biomechanical measurements can help health practitioners, such as physiotherapists, choose appropriate therapy interventions to assess musculoskeletal disorders. To resolve the inconsistencies in the reliability and validity of goniometry values, more research is required.

Effects of ankle exoskeleton assistance during human walking on lower limb muscle contractions and coordination patterns / 生物医学工程学杂志

Lower limb ankle exoskeletons have been used to improve walking efficiency and assist the elderly and patients with motor dysfunction in daily activities or rehabilitation training, while the assistance patterns may influence the wearer's lower limb muscle activities and coordination patterns. In this paper, we aim to evaluate the effects of different ankle exoskeleton assistance patterns on wearer's lower limb muscle activities and coordination patterns. A tethered ankle exoskeleton with nine assistance patterns that combined with differenet actuation timing values and torque magnitude levels was used to assist human walking. Lower limb muscle surface electromyography signals were collected from 7 participants walking on a treadmill at a speed of 1.25 m/s. Results showed that the soleus muscle activities were significantly reduced during assisted walking. In one assistance pattern with peak time in 49% of stride and peak torque at 0.7 N·m/kg, the soleus muscle activity was decreased by (38.5 ± 10.8)%. Compared with actuation timing, the assistance torque magnitude had a more significant influence on soleus muscle activity. In all assistance patterns, the eight lower limb muscle activities could be decomposed to five basic muscle synergies. The muscle synergies changed little under assistance with appropriate actuation timing and torque magnitude. Besides, co-contraction indexs of soleus and tibialis anterior, rectus femoris and semitendinosus under exoskeleton assistance were higher than normal walking. Our results are expected to help to understand how healthy wearers adjust their neuromuscular control mechanisms to adapt to different exoskeleton assistance patterns, and provide reference to select appropriate assistance to improve walking efficiency.

Modelo lineal vs. vectorial: estimación del movimiento mandibular y trabajo mecánico / Linear vs. vector model: estimation of mandible motion and mechanical work

Objetivo: Determinar los momentos de fuerza del haz superficial del masetero (SMH) obtenidos por modelos lineal y vectorial. Métodos: Investigación comparati-va in silico. Se obtuvo la fuerza del SMH con dinamó-metro en 12 pacientes varones adultos jóvenes para calcular el momento de la fuerza y trabajo mecánico a través de simulaciones en JAVA+ con NetBeans8.2. La descomposición de la fuerza fue F.cos α(x,y) y F.cos α(x,y,z) en el modelo lineal y vectorial respectivamen-te. Los momentos de fuerza fueron comparados por ANOVA (p<0,05). Resultados: La fuerza del SMH unila-teral obtenida con dinamómetro (2,5±0,1N) no difirió significativamente del modelo lineal (2,6±0,05N), pero difirió (p<0,001) del vectorial: 1,7, 2,2, 4,2N en x,y,z (general 2,7±0,02N). El momento medio de la fuerza en el modelo vectorial fue -17,9, -15,5, +14,3N.m-2, apuntando a la inclinación mandibular en el eje lateral en dirección caudal anterior, movimiento de inclina-ción en el eje lateral en la dirección cráneo-medial, e inclinación en el eje craneal en la dirección lateral-an-terior. El modelo lineal mostró momento de fuerza de 13,5N.m-2 apuntando un movimiento traslacional en dirección caudal-craneal en el eje anterior-posterior y menor trabajo mecánico del SMH (p=0,012). Con-clusión: Los modelos vectoriales son más eficientes proporcionando datos detallados para estimar los momentos de fuerza y el trabajo mecánico del SMH, y deben incluirse en los algoritmos de cálculo utilizados por dinamómetros (AU)

Objective: to determine the moments of force exerted by the superficial masseter head (SMH) obtained through linear models and vector ones. Methods: comparative in silico research. Data of SMH force obtained with dynamometer in 12 young adult male patients was used to calculate the moment of the force and mechanical work through simulations in JAVA+ performed with NetBeans8.2. Force decomposition was F.cos α(x,y) and F.cos α(x,y,z) in the linear and vector model respectively. The moments of force were compared by ANOVA (p<0.05). Results: Dynamometrical unilateral SMH force (2.5±0.1N) did not differ significantly from the linear model (2.6±0.05N), but differed (p<0.001) from the vector model: 1.7, 2.2, 4.2N on x,y,z (overall 2.7±0.02N). The mean moment of the force in the vector model was -17.9, -15.5, +14.3N.m-2, pointing to mandible's inclination on the lateral axis in anterior-caudal direction, inclination movement on the lateral axis in the cranio-medial direction and inclination on the cranial axis in the lateral-anterior direction. The linear model showed a moment of force of 13.5N.m-2 pointing to translational motion on caudal-cranial direction on the anterior-posterior axis and lower SMH mechanical work (p=0,012). Conclusion: Vector models are more efficient to provide detailed data to estimate the moments of force and mechanical work of SMH and should be included in the calculation algorithms used by dynamometers (AU)

Application of 3d analysis technology of vision system image in sports medicine / Aplicação da tecnologia de análise 3d de imagens do sistema de visão na medicina esportiva / Aplicación de la tecnología de análisis 3d de la imagen del sistema de visión en medicina deportiva

ABSTRACT Background: Objective: The study of sports biomechanics in sports medicine usually requires a special image analysis system (software) to obtain 3D kinematics data. Taking the swimming project in sports medicine as an example, 3D water images in water have always been relatively complicated and difficult. As light travels in different media, it will refract and reflect. When testing underwater movements, if only a land camera or an underwater camera is used for testing, the error caused by light refraction will be larger, which will affect the accuracy of the test data even more. Methods: Taking breaststroke movement as an example, a three-dimensional measurement method based on the Kwon3D movement analysis system is introduced. This method is different from the simple underwater camera test. It is a three-dimensional test method combining a land camera and an underwater camera. Two underwater cameras and two land cameras were used to simultaneously calibrate the water and underwater space with the same calibration frame in the experiment after analyzing and verifying the accuracy of 3D reconstruction. Results: The comprehensive reconstruction error is small, and the average relative error is less than 1%. Conclusions: The application of three-dimensional image analysis technology of vision systems in sports medicine is reasonable and worth promoting. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Antecedente: Objetivo: O estudo da biomecânica do esporte na medicina esportiva geralmente requer o uso de um sistema especial de análise de imagens (software) para a obtenção de dados cinemáticos 3D. Tomando o projeto de natação na medicina esportiva como exemplo, a análise de imagens 3D da água na água sempre foi um teste relativamente complicado e difícil. À medida que a luz viaja em diferentes meios, ela refratará e refletirá. Ao testar movimentos subaquáticos, se apenas uma câmera terrestre ou subaquática for usada para o teste, o erro causado pela refração da luz será maior, o que afetará a precisão dos dados de teste ainda mais. Métodos: Tomando o movimento de nado peito como exemplo, um método de medição tridimensional baseado no sistema de análise de movimento Kwon3D é introduzido. Este método é diferente do teste simples de câmera subaquática. É um método de teste tridimensional que combina uma câmera terrestre e uma câmera subaquática. No experimento, duas câmeras subaquáticas e duas câmeras terrestres foram usadas para calibrar simultaneamente a água e o espaço subaquático com o mesmo quadro de calibração. Depois de analisar e verificar a precisão da reconstrução 3D. Resultados: O erro de reconstrução abrangente é pequeno e o erro relativo médio é inferior a 1% Conclusões: A aplicação da tecnologia de análise de imagem tridimensional do sistema de visão na medicina esportiva é razoável e vale a pena promover. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento.

RESUMEN Antecedente: Objetivo: El estudio de la biomecánica del deporte en la medicina deportiva generalmente requiere el uso de un sistema de análisis de imágenes especial (software) para obtener datos de cinemática 3D. Tomando como ejemplo el proyecto de natación en medicina deportiva, el análisis de imágenes de agua en 3D en el agua siempre ha sido una prueba relativamente complicada y difícil. A medida que la luz viaja en diferentes medios, se refractará y reflejará. Al probar los movimientos bajo el agua, si solo se utiliza una cámara terrestre o una cámara submarina para realizar la prueba, el error causado por la refracción de la luz será mayor, lo que afectará aún más la precisión de los datos de la prueba. Métodos: tomando como ejemplo el movimiento de la brazada, se introduce un método de medición tridimensional basado en el sistema de análisis de movimiento Kwon3D. Este método es diferente de la simple prueba de cámara subacuática. Es un método de prueba tridimensional que combina una cámara terrestre y una cámara submarina. En el experimento, se utilizaron dos cámaras submarinas y dos cámaras terrestres para calibrar simultáneamente el agua y el espacio submarino con el mismo marco de calibración. Después de analizar y verificar la precisión de la reconstrucción 3D. Resultados: el error de reconstrucción integral es pequeño y el error relativo promedio es inferior al 1%. Conclusiones: La aplicación de la tecnología de análisis de imágenes tridimensionales del sistema de visión en la medicina deportiva es razonable y vale la pena promoverla. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.

Influência do arco longitudinal medial na distribuição plantar e na flexibilidade posterior / La influencia del arco longitudinal medial en la distribución plantar y la flexibilidad posterior / The influence of medium longitudinal arch on plant distribution and posterior pliability

RESUMO O objetivo deste estudo foi verificar se a formação do arco longitudinal do pé interfere na distribuição da pressão plantar e na flexibilidade dos músculos posteriores da coxa. O método de estudo foi transversal e as impressões plantares foram obtidas usando o plantígrafo e analisadas segundo o método Viladot. A distribuição plantar e a flexibilidade foram avaliadas pela baropodometria e pelo banco de Wells, respectivamente. Foi observado que crianças com pés cavos apresentam maior flexibilidade quando comparadas às que têm o pé normal (p=0,02); e também que pés cavos apresentam maior pressão, ou seja, maior sobrecarga em calcâneo quando comparados àqueles com o arco plantar normal (p=0,02 membro inferior direito e p=0,03 membro inferior esquerdo). A avaliação do arco longitudinal medial mostra que crianças com pés cavos apresentam maior flexibilidade dos músculos posteriores de membro inferior. Os pés cavos também estão associados com maior descarga de peso em região de calcâneo.

RESUMEN El objetivo de este estudio fue verificar si la formación del arco longitudinal del pie interfiere con la distribución de la presión plantar y la flexibilidad de los músculos posteriores del muslo. El método de estudio fue transversal y las huellas plantar se obtuvieron utilizando el plantigraph y se analizaron según el método de Viladot. La distribución plantar y la flexibilidad se evaluaron mediante baropodometría y el banco de Wells, respectivamente. Se observó que los niños con pies huecos tienen mayor flexibilidad en comparación con aquellos con pies normales (p=0,02); y también que los pies huecos tienen una mayor presión, es decir, una mayor sobrecarga del talón en comparación con aquellos con arco plantar normal (p=0,02 miembro inferior derecho y p=0,03 miembro inferior izquierdo). La evaluación del arco longitudinal medial muestra que los niños con pies huecos tienen una mayor flexibilidad en los músculos posteriores de la extremidad inferior. Los pies huecos también están asociados con una mayor descarga de peso en la región del talón.

ABSTRACT Objective: To evaluate whether the formation of the longitudinal arch of the foot interferes with the distribution of plantar pressure and the pliability of the posterior thigh muscles. Methodology: a cross-sectional study and the footprints were obtained using the footprinting mat and analyzed according to the Viladot method. Plantar distribution and pliability were assessed by baropodometry and Wells' bank, respectively. Results: It was observed that children with cavus feet present greater pliability when compared to those with normal feet (p=0.02). Also, the cavus feet exhibit higher pressure, that is, a greater heel overload compared to those with normal plantar arch (p=0.02 lower right limb and p=0.03 lower left limb). Conclusions: The evaluation of the medial longitudinal arch shows that children with cavus feet have greater pliability of the lower limb posterior muscles. The cavus feet are also associated with higher pressure in the calcaneal region.

Mudança na biomecânica da postura sentada afeta a função pulmonar / Alteración en la biomecánica de la postura sentada afecta la función pulmonar / Change in biomechanics of sitting posture affects the pulmonary function

RESUMO Este trabalho teve como objetivo caracterizar as posturas induzidas por dois sistemas diferentes de cadeira-mesa e analisar seus efeitos na função pulmonar. Trata-se de estudo transversal, descritivo, do tipo sujeito único e intrasséries (A-B, B-A), com coleta em dias consecutivos. Participaram da pesquisa 15 voluntárias e foram utilizados dois sistemas cadeira-mesa: convencional (A) e experimental (B). A postura foi avaliada por meio de fotogrametria em cada um dos sistemas, com imagens analisadas por meio do programa AutoCAD® 2010. Posteriormente, foram calculados os ângulos articulares da postura média das participantes em cada sistema. Os dados posturais e respiratórios foram comparados considerando as diferentes posições adotadas. O sistema cadeira-mesa convencional promoveu dois diferentes padrões posturais: um deles apresentou ângulos articulares similares aos do sistema experimental, com resultados de espirometria semelhantes, e o outro padrão apresentou ângulos corporais de acordo com os padrões esperados com valores de espirometria significativamente inferiores em VEF1, VEF1/CVF e FEFmáx. O sistema experimental diferiu de valores de espirometria da postura ortostática relatados na literatura somente em FEFmáx, sugerindo similaridade de condição postural. Conclui-se que o mobiliário experimental melhorou a função respiratória na postura sentada em comparação com o mobiliário tradicional, podendo beneficiar pessoas em condições especiais, como gestantes, obesos e pessoas com doenças pulmonares crônicas.

RESUMEN Este estudio tuvo como objetivo caracterizar las posturas inducidas por dos sistemas diferentes de silla-mesa y analizar sus efectos sobre la función pulmonar. Se trata de un estudio transversal, descriptivo, de tipo de un solo sujeto e intraseries (A-B, B-A), con recolección en días consecutivos. Quince voluntarios participaron en el estudio, y se utilizaron dos sistemas de silla-mesa: convencional (A) y experimental (B). La evaluación postural se realizó mediante fotogrametría en cada uno de los sistemas, con imágenes analizadas por medio del programa AutoCAD® 2010. Posteriormente, se calcularon los ángulos de articulación de la postura media de las participantes en cada sistema. Los datos posturales y respiratorios se compararon considerando las diferentes posiciones adoptadas. El sistema de silla-mesa convencional promovió dos patrones posturales diferentes: uno presentó ángulos de articulación similares al sistema experimental, con resultados de espirometría similares, y el otro estándar presentó ángulos corporales de acuerdo con los patrones esperados con resultados de espirometría significativamente más bajos en VEF1, VEF1/CVF y FEFmax. El sistema experimental difería de los valores de espirometría de la postura ortostática informados en la literatura solo en FEFmax, lo que sugiere una similitud de la condición postural. Se concluyó que los muebles experimentales pueden mejorar la función respiratoria en la posición sentada cuando se comparaban con los muebles tradicionales, y pueden beneficiar a personas en condiciones especiales, como mujeres embarazadas, personas obesas y personas con enfermedades pulmonares crónicas.

ABSTRACT The objective of this study was to characterize the postures induced by two different chair-desk systems and analyze their effects on lung function. This was a cross-sectional, descriptive study of single subject with intra-series type analysis (A-B, B-A) during consecutive days of data collection. Fifteen volunteers participated using two chair-desk systems: conventional (A) and experimental (B). Postural evaluation was performed in both systems using photogrammetry. These images were analyzed using AutoCAD® 2010, estimating the average position of the joint angles of individuals in each system. These values were analyzed verifying the averages in each posture. Postural and respiratory data were compared by checking whether the different positions adopted by the participants resulted in changes in the spirometry values. Conventional chair-desk system promoted two different postural patterns, considering that one presented joint angles similar to experimental system, with similar spirometry results and the other presented body angles according to the reference of standards and spirometry results significantly lower in FEV1, FEV1/FVC and FEFmax. Experimental system differed from values of literature in standing posture only in FEFmax, suggesting similarity of postural situation. It was concluded that the experimental furniture proved a tool capable of benefiting respiratory function in sitting posture and may be an option to benefit people in special conditions such as pregnant women, obese individuals and people with chronic pulmonary diseases.

Análise eletromiográfica de músculos do complexo do ombro durante exercícios de rotação externa com faixa elástica / Análisis electromiográfico de los músculos del complejo del hombro durante ejercicios de rotación externa con banda elástica / Electromyographic analysis of muscles of the shoulder complex during external rotation exercises with elastic band

RESUMO Na artrocinemática do ombro, o manguito rotador atua estabilizando a cabeça umeral em contato com a cavidade glenoidal, enquanto realiza a translação inferior para contrabalancear a força rotacional promovida principalmente pelo deltoide. Exercícios de rotação externa (RE) vêm sendo utilizados na reabilitação de pacientes com disfunções no complexo do ombro buscando restaurar a artrocinemática. Porém, poucos estudos abordam a utilização da faixa elástica e a avaliação dos músculos da cintura escapular, determinantes para uma cinemática adequada. O objetivo deste estudo é comparar a atividade eletromiográfica (EMG) de músculos do complexo do ombro durante exercícios de rotação externa com faixa elástica. Participaram 11 sujeitos do sexo masculino que foram avaliados durante os movimentos de (1) RE em ortostase; (2) RE com abdução de ombro; (3) RE em decúbito lateral (DL). Os músculos avaliados pela EMG foram: (1) trapézio superior (TS); (2) deltoide médio (DM); (3) deltoide posterior (DP); e (4) infraespinal (IN). A resistência foi determinada por uma faixa elástica cinza calibrada com carga de 5% do peso corporal. A análise dos dados foi realizada no software Biomec-SAS e as estatísticas foram calculadas por meio da Anova de medidas repetidas no software SPSS v20.0. Pôde-se constatar que os músculos TS e DM obtiveram maior atividade EMG durante o exercício de RE com abdução de ombro, o músculo DP durante a RE com abdução de ombro e RE em decúbito lateral, enquanto o IN a obteve durante a RE em ortostase e RE em decúbito lateral.

RESUMEN En la artrocinemática del hombro, el manguito rotador actúa estabilizando la cabeza umeral en contacto a la cavidad glenoidal, mientras realiza la traslación inferior para contrarrestar la fuerza rotacional promovida principalmente por el deltoides. Los ejercicios de rotación externa (RE) se han utilizado en la rehabilitación de pacientes con disfunciones en el complejo del hombro buscando restaurar la artrocinemática. Pocos estudios abordan la utilización de la banda elástica y la evaluación de los músculos de la cintura escapular, determinantes para una cinemática adecuada. El objetivo de este estudio es comparar la actividad electromiográfica (EMG) de los músculos del complejo del hombro durante ejercicios de rotación externa con banda elástica. Participaron 11 sujetos, varones, que fueron evaluados durante el movimiento de (1) RE en ortostasis; (2) RE con abducción de hombro; y (3) RE en decúbito lateral (DL). Los músculos evaluados por la EMG fueron: (a) trapecio superior (TS); (b) deltoides central (DC); (c) deltoides posterior (DP) e (d) infraespinoso (IN). La resistencia se determinó mediante una banda elástica gris calibrada con carga del 5% del peso corporal. El análisis de los datos se realizó con la utilización del software BIOMEC-SAS, y las estadísticas por medio de la Anova de medidas repetidas en el software SPSS v20.0. Se pudo constatar que los músculos TS y DC obtuvieron mayor actividad EMG durante el ejercicio de RE con abducción de hombro, el músculo DP durante la RE con abducción de hombro y RE en decúbito lateral, mientras que el IN durante la RE en ortostasis y en decúbito lateral.

ABSTRACT In shoulder arthrokinematics, the rotator cuff acts on a lower base to counterbalance a glenoid cavity, while performing a lower translation to counterbalance a rotational force mostly provided by the deltoid. External rotation (ER) exercises have been used in the rehabilitation of patients with shoulder joint dysfunction, with the aim of restoring arthrokinematics. Few studies approached the use of the elastic band and the evaluation of the shoulder girdle muscles, essential for suitable kinematics. The objective of this study was to compare the electromyographic activity (EMG) of the muscles from the shoulder complex during external rotation exercises with elastic band. A total of 11 male subjects were evaluated during (1) ER in orthostasis; (2) ER with shoulder abduction; (3) ER with lateral decubitus. The muscles assessed by the EMG were: (a) upper trapezius (UT); (b) middle deltoid (MD); (c) posterior deltoid (PD) and (d) infraspinatus (IS). Resistance was made with a gray elastic band calibrated with a load of 5% body weight. Data analysis was performed using the application software BIOMEC-SAS and statistics for the repeated measures using ANOVA in SPSS version 20.0. The UT and MD muscles were found to have increased EMG activity during ER exercise with shoulder abduction, as well as the PD muscle during ER with shoulder abduction and ER in lateral decubitus, whereas IS had increased EMG activity during an ER in orthostasis and ER in lateral decubitus.

Comparação entre pico de torque e flexibilidade dos membros inferiores de indivíduos com e sem diabetes mellitus tipo 2 / Comparación entre pico de torque y flexibilidad de los miembros inferiores de individuos con y sin diabetes mellitus tipo 2 / Comparison between muscle strength and flexibility of the lower limbs of individuals with and without type 2 diabetes mellitus

RESUMO O objetivo deste trabalho foi comparar o pico de torque e flexibilidade dos membros inferiores de indivíduos com e sem diabetes mellitus tipo 2 (DM2). O método foi o estudo com grupos expostos e não expostos ao DM2. Foram incluídos indivíduos com diagnóstico médico de DM2, encaminhados para eletroneuromiografia, e não expostos ao DM2. Foram excluídos da pesquisa indivíduos com idade superior a 70 anos ou que, por algum motivo, não conseguiram realizar um ou dois dos testes. A amostra foi não probabilística, composta por 64 indivíduos: 34 (53,1%) expostos ao DM2 e 30 não expostos; 50 (78,1%) eram do sexo feminino, a idade média era de 60,7±7,1 anos, e o membro inferior dominante era o direito em 57 (89,1%) dos indivíduos. Comparando indivíduos com e sem diagnóstico de DM2, observou-se redução do torque de flexão à esquerda, em velocidade angular de 120° (25,94±2,26 vs. 33,79±2,4nm, p=0,027, respectivamente). Relatou-se menor valor do torque de dorsiflexão à direita, em velocidade angular de 60°, dos diabéticos em relação aos não diabéticos (10,95±0,89 vs. 13,95±0,96nm, p=0,033, respectivamente). Ao comparar indivíduos com DM2, com e sem diagnóstico de neuropatia diabética periférica (NDP), notou-se maior déficit de flexão entre os indivíduos neuropatas em comparação com não neuropatas (46,57±9,47 vs. 11,63±13,85nm, p=0,049, respectivamente). Não foram encontradas diferenças estatisticamente significativas ao comparar os grupos de expostos e não expostos ao DM2 e diabéticos neuropatas e não neuropatas.

RESUMEN El objetivo de este trabajo fue comparar el pico de torque y la flexibilidad de los miembros inferiores de individuos con y sin diabetes mellitus tipo 2 (DM2). El método fue el estudio con grupos expuestos y no expuestos al DM2. Se incluyeron individuos con diagnóstico médico de DM2, encaminados para electroneuromiografía, y no expuestos al DM2. Se excluyeron de la investigación a individuos mayores de 70 años o que, por algún motivo, no pudieron realizar una o dos de las pruebas. La muestra fue no probabilística, compuesta por 64 individuos: 34 (53,1%) expuestos al DM2 y 30 no expuestos; 50 (78,1%) eran de sexo femenino, la edad media era de 60,7±7,1 años, y el miembro inferior dominante era el derecho en 57 (89,1%) de los individuos. En comparación con individuos con y sin diagnóstico de DM2, se observó reducción del torque de flexión a la izquierda, en velocidad angular de 120° (25,94±2,26 frente a 33,79±2,4nm, p=0,027, respectivamente). Se ha reportado un menor valor del torque de dorsiflexión a la derecha, en velocidad angular de 60°, de los diabéticos con relación a los no diabéticos (10,95±0,89 frente a 13,95±0,96nm, p=0,033, respectivamente). Al comparar individuos con DM2, con y sin diagnóstico de neuropatía diabética periférica (NDP), se notó mayor déficit de flexión entre los individuos neuropáticos en comparación con no neuropáticos (46,57±9,47 vs. 11,63±13,85nm, p=0,049, respectivamente). No se encontraron diferencias estadísticamente significativas al comparar los grupos de expuestos y no expuestos al DM2 y los diabéticos neuropáticos y no neuropáticos.

ABSTRACT To compare the muscle strength and flexibility of the lower limbs of individuals with and without T2DM. The method was a study of the types exposed and unexposed to T2DM. Individuals diagnosed with T2DM, individuals referred to electromyography, and those unexposed to T2DM were included. The exclusion criteria were: individuals over 70 years old; those who for some reason failed to complete one or both tests. The study population consisted of 64 individuals; 34 (53.1%) exposed to DM and 30 unexposed, 50 (78.1%) were female, the mean age was 60.7±7.1 and the dominant lower limb was right in 57 (89.1%) individuals. Comparing individuals with and without a diagnosis of DM, one observed a reduction in the flexion torque on the left at a 120 ° angular velocity in diabetics individuals compared with nondiabetic patients, 25.94±2.26 vs 33.79±2, 4nm, p=0.027, respectively. The reduction in dorsiflexion torque on the right, at a 60 ° angular velocity was observed in diabetics compared with nondiabetic patients, 10.95±0.89 vs. 13.95±0.96nm, p=0.033, respectively. When comparing diabetic individuals with and without a diagnosis of PDN, one observed a greater flexion deficit among neuropathic individuals when compared with non-neuropathic individuals, 46.57±9.47 vs 11.63±13.85nm, p=0.049, respectively. No statistically significant differences were found when comparing groups exposed and unexposed to T2DM, and neuropathic and non-neuropathic diabetics.

Are cursorial birds good kinematic models of non-avian theropods? / ¿Son los pájaros corredores buenos modelos cinemáticos de terópodos no aviares?

Determining kinematics of hindlimbs of theropod dinosaurs has been a challenge. Since cursorial birds are phylogenetically closest to theropod dinosaurs they are commonly used as a kinematic model of theropod dinosaur locomotion. Using a comparative biomechanical approach, we found that cursorial birds have a different morphology of legs than non avian theropodos and that appears to be that felines and ungulates share more morphological properties in the hindlimbs with theropod dinosaurs than cursorial birds. We calculated the ratio between the lower leg and the femur, and the relative length of the tibia and the metatarsus with respect to the length of the femur in cursorial birds, as well as felines, ungulates and non-avian theropods. We found that as the length of the femur increases, the length of the lower leg increases similarly in felines, ungulates and non-avian theropods. On the other hand, existing and extinct cursorial birds did not follow this pattern. This observation suggests that the hindlimb of cursorial birds are not well suited to serve as kinematic models for hindlimb of extinct theropod dinosaur locomotion.

Determinar la cinemática de los miembros pelvianos de los dinosaurios terópodos ha sido un desafío. Dado que las aves corredoras son filogenéticamente más cercanas a los dinosaurios terópodos, son comúnmente utilizadas como modelo cinemático de la locomoción del dinosaurio terópodo. Usando un enfoque biomecánico comparativo, encontramos que las aves corredoras tienen una morfología de pies diferente a la de los terópodos no aviares y parece ser que los felinos y los ungulados comparten más propiedades morfológicas en los pies con los dinosaurios terópodos que las aves corredoras. Calculamos la proporción entre la parte inferior de la pierna y el fémur, y la longitud relativa de la tibia y el metatarso con respecto a la longitud del fémur en aves corredoras, así como en los terópodos no aviares y ungulados. Encontramos que a medida que aumenta la longitud del fémur, la longitud de la parte inferior de la pierna aumenta de manera similar en los terópodos, los ungulados y los terópodos no aviares. Por otro lado, las aves corredoras existentes y extintas no siguieron este patrón. Esta observación sugiere que el miembro pelviano de las aves corredoras no es adecuada para servir como modelos cinemáticos de locomoción del miembro pelviano del dinosaurio terópodo extinto.

Benign ovarian lesions with restricted diffusion / Lesões ovarianas benignas com restrição na difusão

Abstract Developments in magnetic resonance imaging have expanded its role in the assessment of the female pelvis, including the diagnosis of ovarian lesions. In this setting, diffusion-weighted imaging has proven its diagnostic value, which is particularly important in differentiating between benign and malignant ovarian tumors. In general, the latter show restricted diffusion, whereas the former do not. Exceptions include teratomas, endometriomas, hemorrhagic cysts, ovarian abscesses, ovarian infarction, and some benign stromal tumors. The aim of this review is to draw attention to benign ovarian lesions with restricted diffusion, with a special focus on diffusion-weighted imaging pearls and pitfalls.

Resumo Os recentes desenvolvimentos nas técnicas de ressonância magnética aumentaram o seu papel na avaliação da pelve em mulheres, incluindo o diagnóstico de lesões ovarianas. A imagem ponderada em difusão comprovou ter um valor diagnóstico indiscutível, fato particularmente importante na diferenciação entre tumores ovarianos benignos e malignos. Em geral, os últimos têm restrição na difusão, enquanto os primeiros não. As exceções incluem teratomas, endometriomas, cistos hemorrágicos, abcessos ovarianos, enfarte ovariano e alguns tumores benignos do estroma ovariano. Esta revisão tem como objetivo expor lesões ovarianas benignas com restrição na difusão, com especial enfoque nas pérolas e armadilhas da imagem ponderada em difusão.

Evidencia original directa (dinamométrico-tomográfica) de la influencia sitio-específica de la musculatura sobre la estructura ósea: hacia una concepción más amplia del mecanostato / Original dynamometric and tomographic evidence of site-specific muscle effects on bone structure: towards a wider scope on the bone mechanostat concept

Para analizar el impacto directo de la musculatura sobre la estructura ósea se determinaron el área (CtA), la densidad mineral ósea volumétrica (vDMOc) y los momentos de inercia corticales para flexión anteroposterior y lateral (MIap, MIlat) ajustados a CtA, y las relaciones entre MI y vDMOc (de Ê»distribución/calidadʼ, d/c, que describen la eficiencia de la optimización biomecánica del diseño cortical por el mecanostato) en 18 cortes seriados a lo largo de todo el peroné del lado hábil (pQCT), y la fuerza de salto y de rotación externa del pie (dinamometría computarizada) de 22 hombres sanos de 18 a 33 años entrenados en fútbol competitivo por más de 4 años, y de 9 controles etarios no entrenados. Los entrenados tuvieron valores más altos de MI en función de la fuerza de rotación del pie (no de salto), con un ajuste homogéneo para MIap pero variable (más pobre distalmente y más alto proximalmente, en la región de inserción de los peroneos) para MIlat, coincidiendo este último con pobres ajustes de las relaciones d/c (efecto arquitectónico independiente de la rigidez del tejido). Esto evidencia la influencia directa de la tracción de la musculatura peronea sobre la estructura cortical proximal subyacente del hueso y también sugiere que el mecanostato procedería, en este caso, fuera de su conocida concepción como mecanismo regulatorio de la resistencia ósea. (AU)

To analyze the direct impact of muscle contractions on the structure of bones, we determined the cortical cross-sectional area (CtA), volumetric mineral density (vBMDc) and the CtA-adjusted moments of inertia for anterior-posterior and lateral bending (MIap, MIlat), and the ʻdistribution/qualityʼ (d/c) relationships between MIs and vBMDc (which describe the efficiency of the biomechanical optimization of cortical design by bone mechanostat) in 18 serial scans taken throughout the fibula of the dominant side (pQCT), and the jump and the foot-lateral-rotation forces (computed dynamometry) of 22 healthy men aged 18-33 years, who had been trained in competitive soccer for more than 4 years, and of 9 untrained, agematched controls. Trained individuals showed higher MI values as a function of the rotative force of the foot (not the jumping force). The adjustment of these relationships was homogeneous for MIap throughout the bone, but variable (poorer distally and higher proximally, at the insertion area of peroneus muscles) for MIlat, this latter being paralleled by poor adjustments of the corresponding, d/c relationships (architectural effect independent of tissue stiffness). These findings,1. Show the direct influence of the traction force of peroneal muscles on proximal fibula structure close to the insertion area, and 2. Suggest that, in the studied conditions, the bone mechanostat would proceed beyond its known conception as a regulatory mechanism of structural bone strength. (AU)

Influencia de parámetros de diseño sobre el comportamiento biomecánico de un implante dental corto / Influence of design parameters on the biomechanical behavior of a short dental implant

Introducción: Los implantes dentales deben transmitir esfuerzos al tejido óseo y generar deformaciones que favorezcan el equilibrio entre los procesos de formación y reabsorción ósea. Debido al alto número de pacientes que presentan maxilares con dimensiones reducidas, es necesario estudiar el comportamiento biomecánico de implantes dentales cortos. Objetivos: Evaluar el efecto de los parámetros de diseño: diámetro máximo, longitud de la interfaz hueso-implante y altura del filete de la rosca sobre el comportamiento biomecánico de un nuevo diseño de implante dental corto. Métodos: Los modelos tridimensionales del implante dental corto fueron creados usando el software Autodesk Inventor Profesional versión 2011 (Autodesk Inc, California, USA) y analizados con el software de elementos finitos Autodesk® Algor® Simulation (Autodesk Inc, California, USA). Resultados: Los niveles máximos de esfuerzos equivalentes de von Mises se obtuvieron, en el hueso cortical peri-implantar. Las cargas aplicadas al implante generaron, en el hueso trabecular peri-implantar, los mayores esfuerzos equivalentes de von Mises en la región apical y los menores valores en la región próxima al hueso cortical. Además, los mayores valores de deformación se obtuvieron en el hueso trabecular para todos los modelos estudiados. Conclusiones: En general, los resultados de las simulaciones mostraron que la mayoría de los modelos estudiados generan esfuerzos y deformaciones en el hueso cortical peri-implantar en niveles que estimulan el crecimiento y la remodelación ósea. No obstante, en algunas de las variantes simuladas se observaron niveles de esfuerzos y deformaciones, en zonas del hueso trabecular peri-implantar, que pueden provocar pérdida ósea en los maxilares. Las variables diámetro del implante y altura del filete de la rosca exhibieron la mayor influencia sobre los esfuerzos y deformaciones máximas generados en el tejido óseo(AU)

Introduction: Dental implants should transmit stresses to the bone tissue and generate strain levels that favor the balance between the bone formation and bone resorption processes. Due to the high number of patients with reduced jawbone dimensions, it is essential to study the biomechanical behavior of short dental implants. Objective: Evaluate the effect of the design parameters: Maximum diameter, Length of the bone-implant interface and Thread depth on the biomechanical behavior of a new design of short dental implant. Methods: The 3D models of the short dental implant were created using Autodesk Inventor Professional software (Autodesk Inc, California, USA) and analyzed by finite elements with Autodesk® Algor® Simulation software (Autodesk Inc, California, USA). Results: The maximum von Mises equivalent stress was obtained in peri-implant cortical bone. The loads applied to the implant generated in peri-implant cancellous bone, the highest von Mises equivalent stress in the lower end of the apical region and the lowest stress values in the region next to the cortical bone. In addition, the highest strain values were obtained in cancellous bone for all models under study. Conclusions: In general, the simulation results showed that most of the models under study generate stresses and strains in peri-implant cortical bone at levels that stimulate bone growth and bone remodeling. However, for some models, it was observed levels of stress and strain in peri-implant cancellous bone that could provoke the bone onset. The variables Implant diameter and Thread depth exhibited the greatest influence on the maximum stresses and strains obtained in the bone tissue(AU)

Relationship between the biomechanical properties of the cornea and anterior segment measurements

OBJECTIVE: To evaluate the relationship of biomechanical properties, corneal hysteresis and corneal resistance factor with age, sex and various corneal parameters measured with a Pentacam in normal subjects. METHODS: A total of 226 eyes from 113 patients were enrolled in this study. The subjects underwent Ocular Response Analyzer and Pentacam evaluations. A varying-intercept multilevel regression was implemented using Bayesian inference. The predictor variables were age, sex, central corneal thickness, corneal volume at a 7-mm diameter, anterior chamber angle and volume, anterior chamber depth, mean radius of the corneal curvature and corneal astigmatism. RESULTS: Corneal hysteresis ranged from 5.5 to 14.8 mmHg (mean 10.42±1.74 mmHg), and the corneal resistance factor ranged from 5.7 to 15.5 mmHg (mean 10.23±1.88 mmHg). No predictor variable other than gender and central corneal thickness had a significant correlation with either corneal hysteresis or corneal resistance factor. Corneal hysteresis was positively associated with female sex and with central corneal thickness, and corneal resistance factor was positively associated with central corneal thickness. CONCLUSION: Despite the associations found, only a small fraction of the variance in biomechanical measurements could be explained by the descriptors that were evaluated, indicating the influence of other corneal aspects on the biomechanical characteristics.

Análisis cinemático del movimiento de flexión-extensión del dedo pulgar mediante un mecanismo de palanca / Cinematic analysis of the flexion-extension movement of thumb finger by a bar mechanism

Introducción: La recuperación del grado de movilidad de las estructuras internas de la mano es un factor importante en la rehabilitación de pacientes. Objetivo: Estudiar la cinemática del movimiento de flexión-extensión de las estructuras internas del dedo pulgar a través de un mecanismo de palanca. Métodos: Se emplearon los métodos de análisis y síntesis de la teoría de mecanismos y máquinas. El dedo pulgar se definió como una cadena cinemática de tres grados de libertad. Resultados: La velocidad y aceleración máxima se obtuvieron en el recorrido de la posición extrema superior hasta la de agarre. La velocidad angular para la unión metacarpo-falángica (MCP) fue 9.12 rad/s, 18.10 rad/s en la inter-falángica proximal (PIP) y 10.07 rad/s en la inter-falángica distal (DIP); la velocidades lineal para la unión metacarpo-falángica (MCP) fue 0.45 m/s, 0.73 m/s en la inter-falángica proximal (PIP) y 0.30 m/s para la inter-falángica distal (DIP); as aceleraciones para MCP fue 4.10 m/s2 en el caso de la tangencial, 187.61 m/s2 para la normal; en la inter-falángica proximal (PIP) fue de 13.3 m/s2 en el caso de la tangencial, 163.71 m/s2 para la normal; y para la inter-falángica distal (DIP) fue de 3.04 m/s2 en el caso de la tangencial, 31.52 m/s2 para la normal. Conclusiones: Se definen las ecuaciones fundamentales que permitieron el obtener las velocidades y las aceleraciones durante el movimiento de flexo-extensión de las uniones del mecanismo, en las posiciones principales del dedo pulgar(AU)

Introduction: The recuperation of the range of mobility of the hand is an important factor in the patient rehabilitation. Objective: To study the kinematics of the flexion-extension movement of the thumb by a bar mechanism. Methods: The methods of analysis and synthesis of the theory of mechanisms and machines were used. The thumb was defined as a kinematic mechanism of three degrees of freedom. Results: The maximum speed was obtained between the upper position and the intermediate (or gripping) position. The angular velocities for the metacarpophalangeal joint (MCP) were 9.12 rad/s, in the proximal inter-phalangeal (PIP) of 18.10 rad/s and the distal inter-phalangeal (DIP) 10.07 rad/s. Also the linear velocities behaved as follows for the metacarpophalangeal joint (MCP) was 0.45 m/s, in the proximal inter-phalangeal (PIP) of 0.73 m/s to the distal inter-phalangeal (DIP) 0.30 m/s. Also the maximum accelerations are also obtained from the upper-end position to the intermediate (or gripping). Accelerations for the metacarpophalangeal joint (MCP) were 4.10 m/s2 for tangential component, 187.61 m/s2 for normal component; in the proximal phalangeal inter (PIP) was 13.3 m/s2 for tangential component, 163.71 m/s2 for normal component; and inter-phalangeal distal (DIP) were 3.04 m/s2 for tangential component, 31.52 m/s2 for normal component. Conclusions: The fundamental equations that allowed obtaining the velocities and accelerations during the movement of flexion and extension of the mechanism joints in the main positions of thumb were defined(AU)

Fundamentos biomecánicos de la lucha deportiva / Biomechanical fundamentals of sports wrestling

La práctica de la lucha ha permitido elaborar las estructuras más efectivas de las acciones técnicas, las cuales pueden ser divididas en acciones de ataques, defensas y contraataques. Los luchadores que tienen un buen desarrollo técnico dominan a menudo a contrarios que los superan en fuerza física. Con dicho fin, recurren a movimientos que, con su ejecución correcta y con una exacta aplicación y dirección de las fuerzas interiores y exteriores, forman una estructura de la llave, defensa y contrallave que aseguran una ventaja en fuerza o permiten ganar tiempo. Para desentrañar las leyes de la técnica de la lucha es necesario analizar todos los movimientos fundamentales de los luchadores. Este análisis es conveniente realizarlo, en primer lugar, con el estudio de la interacción de la fuerza mecánica que surge en la ejecución de las acciones técnicas. Por ello, el objetivo del estudio es plantear los fundamentos biomecánicos en el proceso de los ejercicios físicos y el análisis de las acciones motoras del luchador como sistema de movimientos activos recíprocamente relacionados(AU)

The wrestling practice has allowed the elaboration of most effective structures of the technical actions, which can be divided into actions of attacks, defenses, and counterattacks. The fighters who have a good technical development often dominate opponents who overcome them in physical strength. To this end, they resort to movements that, with their correct execution and with an exact application and direction of the internal and external forces, form a technique structure, defense and counter-technique that assure an advantage in strength or allow time. To unravel the technique laws of wrestling it is necessary to analyze all fundamental movements of the fighters. This analysis is convenient to do, first, with the study of mechanical force interaction that arises in the technical actions execution. Therefore, the study objective is to propose the biomechanical fundamentals to process of physical exercises and motor actions analysis in wrestling as a system of active movements related reciprocally(AU)

Change of Pronation Angle of the Subtalar Joint has Influence on Plantar Pressure Distribution / Alteração do Ângulo de Pronação da Articulação Subtalar tem Influência na Distribuição de Pressão Plantar: Um Estudo Preliminar

Abstract Several studies have investigated the relationship between heel pronation with plantar pressure during gait. With a degree of variability and influence of the footwear, usually excessive pronation is associated with higher mechanical loads. However, larger loads are commonly associated with pronation. his study aims to compare the plantar pressure distribution among individuals with different pronation angles of the subtalar joint angle during gait with controlled speed. he maximum angle of the subtalar joint was determined by capturing images in the frontal plane and the pressure plant peaks were acquired by EMED pressure platform. he pronated group showed pressure plant peaks significantly higher in the lateral heel area (18%; p=0.031), medial heel (17%, p=0.034), lateral midfoot (30%; p=0.032) and medial midfoot (41%; p=0.018) when compared to the control group. Excessive pronation of the subtalar joint caused changes in plantar pressure distribution, and an increase in pressure plant peaks, especially in the heel and midfoot regions. This demonstrates the need for a specific care of this population, mainly because the increased pressure plant peaks is related to pain in the feet and onset of injuries.

Resumo Diversos estudos investigaram a relação da pronação da articulação subtalar com a pressão plantar na marcha. Com certo grau de variabilidade e influência do calçado, geralmente uma pronação excessiva está associada a cargas mecânicas mais elevadas. Contudo, popularmente se associa qualquer índice de pronação com aumento das cargas. Neste estudo buscamos comparar a distribuição de pressão plantar entre indivíduos com diferentes comportamentos do ângulo de pronação da articulação subtalar durante a marcha com velocidade controlada. O ângulo máximo de pronação da articulação subtalar foi determinado por meio da aquisição de imagens no plano frontal e os picos de pressão plantar foram adquiridos através da plataforma de pressão EMED. O grupo pronado apresentou picos de pressão plantar significativamente mais elevados na região do calcanhar lateral (18%; p=0,031), do calcanhar medial (17%, p=0,034), do mediopé lateral (30%; p=0,032) e do mediopé medial (41%; p=0,018) quando comparado ao grupo controle. A excessiva pronação da articulação subtalar provocou alterações na distribuição de pressão plantar, com aumento nos picos de pressão plantar, principalmente nas regiões do calcanhar e do mediopé. Isto demonstra a necessidade de um cuidado especifico em relação e este público, principalmente pelo aumento dos picos de pressão plantar estar relacionado com dores nos pés e com o surgimento de lesões.

Corneal properties and glaucoma: a review of the literature and meta-analysis / Propriedades da córnea e glaucoma: revisão da literatura e meta-análise

ABSTRACT Purpose: Studies have suggested that corneal biomechanical properties influence intraocular pressure (IOP) measurements, namely central corneal thickness (CCT) and corneal hysteresis (CH). The present study aimed to investigate the associations of CH and CCT with glaucoma development. Methods: We performed a review of the literature and meta-analysis of observational studies (2006-2016) that included both adult glaucoma patients and controls and reported CCT and CH as outcomes. Nineteen studies were conside red eligible, and the mean difference (MD) between groups (patient and control) for both variables was used for statistical analyses. Results: A total of 1,213 glaucoma and 1,055 healthy eyes were studied. Quan titative analysis suggested that CH was significantly lower in the glaucoma group than in the control group (MD=-1.54 mmHg, 95% CI [-1.68, -1.41], P<0.0001). Additionally, CCT was significantly lower in the glaucoma group than in the control group (MD=-8.49 µm, 95% CI [-11.36, -5.62], P<0.001). Conclusion: Corneal properties appear to differ between glaucoma patients and healthy controls. Our results emphasize the importance of corneal biomechanical properties in IOP interpretation and should support further studies on the influence of CH and CCT in glaucoma screening and diagnosis.

RESUMO Objetivo: A literatura sugere que as propriedades biomecânicas da córnea, nomeadamente a espessura central da córnea (ECC) e a histerese corneana (HC), influenciam a medição da pressão intraocular (PIO). Este estudo teve como objetivo investigar a associação entre a ECC e a HC e o desenvolvimento de glaucoma. Métodos: Revisão da literatura e meta-análise. Foram incluídos estudos observacionais, publicados entre 2006 e 2016, que integrassem um grupo controle e um grupo de pacientes com glaucoma em que estes dois grupos apresentassem, igualmente, a ECC e a HC como parâmetros. Dezenove estudos foram considerados elegíveis e a diferença média (MD) daqueles parâmetros nos dois grupos foi utilizada para análise estatística. Resultados: Estudaram-se um total de 1.213 olhos com glaucoma e 1.055 olhos saudáveis. A análise quantitativa revelou que a HC é significativamente mais baixa no grupo de doentes com glaucoma quando comparada com o grupo controle (MD=-1,54 mmHg, intervalo de confiança de 95% [-1,68-1,41], P<0,00001). A ECC foi, também, significativamente mais baixa no grupo glaucoma quando comparada com os indivíduos saudáveis MD=-8,49 µm, intervalo de confiança de 95% [-11,36, -5,62], P<0,001). Conclusão: Os pacientes com glaucoma parecem possuir propriedades corneanas diferentes das que apresentam os indivíduos saudáveis. Os resultados enfatizam a importância das propriedades biomecânicas da córnea na interpretação da PIO e devem contribuir para novos estudos sobre a influência da HC e da ECC no rastreio e diagnóstico do glaucoma.

Biomechanical Parameters in Children with Unilateral and Bilateral Clubfoot during Vertical Jumps

Abstract Gait analysis may offer information to choose the best exercise-based clinical intervention for the children with clubfoot. However, other motor abilities are not commonly investigated. The aim of this research was to analyze the biomechanics of countermovement vertical jumping in clubfooted children who had undergone surgery. Fourteen children with idiopathic clubfoot were selected and the control group consisted of 11 children. Clubfooted children showed less dorsiflexion in the jump preparation phase. In the impulse phase, this group showed more knee flexion and less plantarflexion associated with less magnitude of vertical reaction force and less muscular activity in the gastrocnemius medialis. In the landing phase, for clubfoot group, we found high loading rate for the first peak of vertical force, less plantarflexion and more knee flexion. Understanding the biomechanical changes of vertical jump landing should assist in better targeting of physical and sporting activities of this population.(AU)